The present invention relates to transmission belts or chains of the toothed type for coupling spaced gears or sprockets in installations such as timing chains and other positive drive systems. More particularly, the invention relates to an improved composite drive chain having a unitary molded plastic body reinforced with spaced steel cables embeded in the molded plastic body.
Plastic belts or other molded chains are known which are employed in certain transmission means including timing devices and other synchronized drive systems. Molded plastic drive chains have several inherent advantages over the previous link belt or other metallic silent chain drives. Molded plastic drives, for example, eliminate the need for lubrication and are further characterized by lightweight, minimal backlash, silent running, rust proof operation and the avoidance of metal to metal contact.
The silent chain of the present invention represents a further improvement over such molded plastic chains including the chain shown in applicant's issued U.S. Pat. No. 4,026,162. That chain had a flexible molded body reinforced with steel cables and included integral molded teeth shaped for closely engaging each of the driven sprocket teeth. The belt of the present invention represents an improvement by having an improved design of the molded plastic portion including split teeth for significantly minimizing backlash between the driven elements, and, additionally has an improved chain cross-section including partially molded flanges to further eliminate the need for any belt guiding flanges on the connected sprockets or pulleys.
Accordingly, an object of the present invention is to provide an improved lightweight composite plastic and cable chain capable of operating with minimal backlash.
Another object of the present invention is to provide an improved composite plastic and cable chain having integral flanges for reliable operation and improved pulley guidance.
Another object of the present invention is to provide an improved, simplified, silent, corrosion proof composite plastic and cable driven belt.
Another object of the present invention is to provide an improved toothed drive belt with an improved weight to strength relationship.
Another object of the present invention is to provide an improved composite lubrication-free drive chain.
Another object of the present invention is to provide an improved composite and positive drive chain adapted for being formed in loops of differing size.
Other and further objects of the present invention will become apparent upon an understanding of the illustrative embodiments about to be described or will be indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.